Without limiting the scope of the invention, its background is described in connection with biofuel formation.
A number of investigators have been developing alternative fuels to partially or completely replace fossil fuels. As proven reserves of fossil fuel reservoirs decrease, a great need has arisen for the development of fuels based on renewable sources.
One such renewable source of energy is taught in U.S. Pat. No. 7,371,558, issued to Cervin, et al. for a process on the biological production of 1,3-propanediol with high yield. Briefly, a microorganism useful for biologically producing 1,3-propanediol from a fermentable carbon source at higher yield is taught. Cofactor complexity required the use of whole cell catalyst for an industrial process to produce 1,3-propanediol. A microorganism is included with disruptions in specified genes and alterations in the expression levels of specified genes that is useful in a higher yielding process to produce 1,3-propanediol.
U.S. Pat. No. 7,285,403, issued to Jeffries, et al., teaches a xylose-fermenting recombinant yeast strain. Briefly, xylose-fermenting recombinant yeast strains are taught that express xylose reductase, xylitol dehydrogenase, and xylulokinase and have reduced expression of PHO13 or a PHO13 ortholog, as well as methods of fermenting xylose to obtain ethanol using the recombinant yeast strains. One specific embodiment of the invention is a recombinant xylose-fermenting strain of Saccharomyces cerevisiae expressing Pichiastipis XYL123 and having a transposon or disruption mutation in PHO13.
Another such renewable source is taught in U.S. Pat. No. 5,697,986, issued to Haas, for fuels as solvents for the conduct of enzymatic reactions. Briefly, this patent describes a method of producing biofuels by carrying out the enzymatic transesterification of fatty acid-containing materials directly in automotive fuels. The method includes forming a reaction mixture of automotive or related fuel, fatty acid-containing substances, alcohol and lipase, all in amounts effective for a reaction to occur, and water in an amount sufficient to confer enzymatic activity, incubating the reaction mixture for a time and at a temperature sufficient for transesterification between the fatty acid-containing substance and the alcohol to occur, and separating the by-products from the biofuel portion of the mixture.
Yet another method is taught in United States Patent Application No. 20080092829, filed by Renninger, et al., for fuel components, fuel compositions and methods of making and using same that includes a fuel composition with at least a C5 isoprenoid compound or its derivative and a conventional fuel additive. The C5 isoprenoid compound or its derivative can be used as a fuel component or as a fuel additive in the fuel composition. The fuel composition may further be a conventional fuel component selected from a diesel fuel, jet fuel, kerosene or gasoline. Methods of making and using the fuel composition are also disclosed.
Another method is taught in United States Patent Application No. 20080071125, filed by Li for a method of converting triglycerides to biofuels. Briefly, the application discloses a triglyceride-to-fuel conversion process that includes the steps of (a) pre-conditioning unsaturated triglycerides by catalytic conjugation, cyclization, and cross-link steps; (b) contacting the modified triglycerides with hot-compressed water containing a catalyst, wherein cracking, hydrolysis, decarboxylation, dehydration, aromatization, or isomerization, or any combination thereof, of the modified triglycerides produce a crude hydrocarbon oil and an aqueous phase containing glycerol and lower molecular weight molecules, and (c) refining the crude hydrocarbon oil to produce various grades of biofuels. The biofuel composition may include straight-chain, branched and cycloparaffins, and aromatics. The paraffins are derived from conversion of triglycerides and the aromatics are derived from conversion of either triglycerides, petroleum, or coal.
United States Patent Application No. 20060236595, filed by Nakamura teaches a biofuel conversion process. Briefly, a process, method, apparatus and materials for efficient conversion of waste vegetable oils into biofuel that does not use methanol as a reactant or catalyst is disclosed. The biofuel is mixed with kerosene or heavy oil to form a stable diesel fuel grade fuel that is mixable with diesel fuel. In addition, the process and apparatus are also applicable to the conversion of virgin vegetable oils and other waste or virgin oils, such as used motor oil, into fuels or fuel additives.